Modern Sticker Printing Methods

In the custom sticker printing industry there are five types of techniques used.

Screen Printing

Flexography

Letterpress

Offset

Digital

Screen Printing is a simple form of printing with a screen; originally silk which is still used, is now also done with synthetic material screens. This is a very basic and uncomplicated form of printing which is popular for custom stickers. It can be done by hand and is usually monochromatic, or limited to just a few colors. Pertaining to custom stickers, the inks used are known as ultra-violet cured pigmented colors. The image to be printed is cut out of a stencil, thus creating a positive of the image to be printed. This stencil is laid over the substrate, or the material onto which the image is to be printed. The screen is then laid over the stencil; the appropriate amount of ink is administered and then pressed through the screen with a rubber blade, also known as a squeegee. For monochromatic prints this process is only done once, for prints with multiple colors the process has to be repeated for each color after the last color has dried.

Flexography is another name for surface printing. This process is widely used for commercial label printing as it allows for fast and high volume printing. This is done somewhat like a stamp in that there must be a reversed master image used to print. A specified amount of ink is applied to the master for each print; the master makes contact with the substrate by rolling over it and leaving the intended image. The term "flexo" comes from the flexible nature of the printing process itself. This process was initially developed for printing on uneven surfaces such as cardboard, in order to have a quality print on such a surface it is necessary to have a method of printing that allows constant and even contact with the print surface. Flexographic printing in the sticker industry is largely intended for indoor use, or limited use, such as in shipping or packaging. This includes paper, boxes, food packaging, plastic labels for bottles, plastic bags and all kinds of other commercial uses besides custom sticker printing.

Letterpress printing is another standard of printing for stickers. This type of printing is also known as relief printing. This means that image printed is taken from a raised surface. More simply you can imply the process from the name itself; you actually press the letter to create the image. This is the technique used for moveable type printing and for set block printing as well. The Guthenberg Bible, the first book ever printed was done with this process in 1456, as Johannes Gutenberg was the one who invented the moveable type block printer. This was the standard for printing for the next five centuries. Letterpress is designed for simple, mass printing projects. This process only allows for one color to be applied at a time, so these kinds of projects are typically monochromatic or limited to two colors.

Offset printing implies the definition of the process in its name. What offset printing means is that there is an extra step in the process. The image to be printed is not applied directly; the transfer is offset, meaning the image being transferred goes from the plate cylinder to the rubber transfer cylinder before it is affixed to the actual intended print surface. The offset printing process is used in concert with the lithographic printing process. Offset printing offers a variety of strong and vibrant colors that may be used for more eye-catching designs; this effect is produced using a four color process.

Digital printing is the latest evolution in printing. This kind or printing allows the most flexibility in manipulation of the print image before it is printed. The print is a reproduction of a digital image. Digital printing is completely customizable from one print to the next, allowing for changes in color, editing of the image and limits the amount of wasted chemicals and paper used in the process. Digital printing inks are different from other inks used in other processes in that they are not absorbed into the print material; rather they form a layer on top of the print material.

The inks used for custom sticker printing are specialized for outdoor use to withstand ultraviolet rays and weather changes. Digital printing allows for a wide array if colors to be used. Digital printing is easy and widely used for commercial purposes such as custom sticker printing as well as personal use and small business use. The greatest advantage to digital printing is the portability of the file and not having a need for making a master plate from which to print.